high/low lightbar

[SirenEnthusiast360]

I don't know if this is even possible but is there a way to make a vehicluar lightbar alternate between the left and right sides when a siren is in high/low?

[loudmouth]

all i can think of is just have the light bar on ullternating flash of quad flashes or double flashes. most light bars are sequnced threw a power pack that runs all the light and some alow to slect diffrent patterns while others just do flash patterns in random sequince.

[SirenMadness]

I think that I have seen that in some movies. I don't know for sure, though I think that there must be electronic equipment putting the two things into synchronization. I am not yet sure of that type of thing, nor have I seen it being used yet.

[zetronist]

I guess my question would be, "why"?

Though it would look cool, I am sure, the fact is that most agencies rarely use Hi-Lo on the sirens that still have that function. Hi-Lo just doesn't work on an electronic. (European horns are an entirely different story, because they are horns).

Besides, most electronics today don't have Hi-Lo as a feature anymore. It's been replaced by sounds like "Phaser" or "HyperYelp" which are more effective at short ranges for penetrating traffic.

Just my $.02

John

PS-- I remember the days when the Federal Interceptor had Wail, Yelp and Alert (before the days of Hi-Lo). Alert was just a steady tone. I'm not even sure what it was used for-- maybe a tone before you spoke on the PA to get everyone's attention?? Federal switched to Hi-Lo in the early 1970's. I remember reading on one of their documents that "Alert can still be accomplished on the siren by holding in the manual button"

[SirenMadness]

Hi-lo is also a somewhat more strenuous signal for the voice coil to perform, depending on the variation between the two tones. BTW, I think that Britain has some electronic hi-lo-performing devices.

[Jim_Ferer]

But could it be done to make a different visual signal to go with a different audio signal? Sure it could, why not? You'd almost have to have siren and lights the same brand, and designed to work together. I'd be surprised if anybody bothered.

My ideal warning set-up; the Japanese fire truck siren, Martinshorns for intersections, and mongo LED lightbars.

[q2bman]

8) The answer is maybe. I had a set of undersover strobe on a police vehicle. I tied the flash pattern input of the strobe power supply to the siren selector switch. (i would not recomend this). Somehow i didn't blow the diodes and it worked. I left it that way and it was sweet. When the siren, an older SVP, was switched to wail the strobes came on quad left and right, yelp was fast double flash left and right, and phaser was very fast single flash.

On the newer led lightbars, you could do this as well, maybe with the aid of some 9 volt optoisolators and some relays. This would be safer than hooking straight up to the selector switch. The voltage through the selector sw would activate the optoisolators and then the relays. This would change the pattern of the led bar or strobe bar. Of coarse, the Hi-Low and Alternateing signal would depend on the signals the lightbar had to ofer.

Kind of cool to be able to change the sound and light configuration to gain more attention.

ROBERT, Do not remind me of your wail theory!!!

[Castlevania2006]

The ones we have are the thin ones but the weird part is that the blue side is half an inch below the red line lights I get headaches when I see these at night

[Daniel]

Some German hi-lo sirens could in theory drive flashing lights in unison with the sound. Air-powered Martinshorns couldn't do this unless a switch were mounted inside the cam/valve assembly. Bosch made electric sirens with two flat diaphragm horns, basically giant motorcycle horns, and these could drive lights if the relay were sufficient to carry the load.

[q2bman]

I noticed when you look in the mirror at an led lightbar the blue lights look physicly lower than the red lights. However, when you look at the lightbar the leds are actually one the same plane. Must be something to do with the wave lenghts and the mirror.